After I concluded a talk a few days ago, a man and woman approached me. "We need to thank you for today," the man said. "We've been deeply touched by your words." My automatic reaction was to take the "aw shucks" route, minimizing what I'd done.

But the woman interrupted my shallow expression of humility: "No. Please listen carefully. It's important that we give and that you receive from us our gratitude, what this hour has meant to us. God has spoken through you into a very bruised part of our lives, and we want to affirm his wonderful gift."

The words morphed into tears and the two clutched each other. "We will never be the same because of what we heard today."

Suddenly I realized that this was not simply two people being courteous. And it was certainly not a moment for me to casually dismiss. The three of us were involved in something significant. I've come to call it the thankful exchange.

When we were children, most of ...